      :w 0 :h 0
      :sound-on? true
      :px-per-ms 0.1
-     :scroll-touch-id nil
+     :scroll {:distance 0 :speed 0 :friction 0.9 :touch-id nil}
      :start start
      :playhead start}))
 

       :off nil
       :touch-id (touch :touch-id)})))

(defn start-note
  [touch {notes :notes :as instrument}]
  (if-let [new-note (touch->note instrument touch)]

(defmethod handle-touch "touchmove"
  [{touch-id :touch-id :as t} touches out-c]
  (go
   (if (scrolling-touch? touches t)
     (let [{{x1 :x y1 :y} :position} (get touches touch-id)
           {{x2 :x y2 :y} :position} t
           scroll (-> t (assoc :x-distance (- x1 x2)) (assoc :y-distance (- y1 y2)))]
